The present invention relates to the field of electronic connectors. In particular, the present invention is directed to a safety guard for a type-N coaxial connector that prevents casual human contact with a center pin of the coaxial cable.
Conventional coaxial connectors are typically manufactured with male connectors having a pin in the center of the connector. Recently, the Semiconductor Equipment Standards Organization promulgated a set of safety guidelines for the semiconductor industry entitled, xe2x96xa1SEMI S2-93, Safety Guidelines for Semiconductor Manufacturing Equipmentxe2x96xa1, published in 1994. One of the areas addressed by SEMI S2-93 relates to radio frequency (RF) equipment using greater than 30 volts root-mean-square (RMS) or 42.2 volts peak RF power. According to paragraph 5.4 of the guidelines, any equipment using greater than 30 volts RMS or 42.2 volts peak, as well as other specified equipment, should be provided with physical barriers or safety interlocks at the point of hazard to effectively protect persons from exposure to the hazards associated with the specified equipment. Additionally, according to SEMI S2-93, if the physical barrier does not require a tool to obtain access, the interlock solution is mandatory.
Most connector manufacturers have chosen to take the interlock approach in complying with the safety guidelines set forth in SEMI S2-93 even in situations where the interlock solution is not required by the standard. Using an interlock arrangement requires substantial reconfiguration of the standard coaxial connector. Conventional interlock designs typically require modification of both the male and female connector ends to ensure proper mating of the connectors while providing the required safety guard. Interlock designs typically require substantial modifications to the system to include protective housings, microswitches, PCBs, cables and harnesses to accommodate the interlocks. Additionally, there are guard designs of various connector manufacturers that are single source/proprietary and require the use of a relatively expensive non-standard male and female connector mating set. By adopting an interlock solution or proprietary guarded connectors, most manufacturers have unnecessarily increased the complexity and cost of providing coaxial connectors that meet the safety guidelines set forth in SEMI S2-93. What is needed is a simple and cost-effective solution that provides the safety features set forth in the standard, without requiring unnecessarily complex and expensive interlock and connector designs.
The present invention provides an improved connector design that meets the safety guidelines of SEMI S2-93 without requiring expensive and complex interlocking connectors that are not adaptable to conventional coaxial connectors. In particular, the present invention provides a guard for a type-N RF coaxial connector that may be inserted into an existing male coaxial cable connector, or which may be provided together with the connector assembly so that when the connector is installed, it will be provided with the appropriate safety guard. In addition to being easily retrofitted onto existing connectors, the safety guard of the present invention provides a simple and cost-effective solution for meeting the safety guidelines relating to RF connectors. Moreover, the present invention implements a safety guard that is used on the male connector only, thereby alleviating the additional expense incurred by modifying both the male and female connectors, as required by proprietary guarded connector designs.
In effect, the present invention provides an intrinsically safe RF coaxial connector that does not require an interlock structure, wherein an operator or user cannot reach the hazard, i.e., the conducting center pin of the coaxial cable, per United Laboratories Articulate Finger test as set forth in UL 507, thereby removing the point of hazard.